Ornamental fish - aquarium fish

A general term for fish that are kept as pets in aquariums and ponds, and are enjoyed for their beauty and unique habits. They are broadly divided into freshwater and saltwater fish. Representative freshwater fish include goldfish, koi carp, and tropical fish. Goldfish were first bred in China in the 8th and 9th centuries, and after being introduced to Europe in the early 17th century, they became a global ornamental fish. Many varieties have been cultivated, and there are more than 20 species in Japan. Nishikigoi (colored carp), also called irogoi (colored carp), began in the first half of the 19th century in what is now Nagaoka City, Niigata Prefecture (mainly in the former Koshi County in the southeast), where colored versions of magoi were bred. Since then, the number of varieties has increased through crossbreeding, and there are now several dozen species, and they are currently exported to foreign countries along with goldfish. Ornamental tropical fish are native to the tropical regions of Asia, Africa, Central and South America. Many of the fish that are kept as ornamental fish include killifish, cichlids, catfish, loaches, and characins. Tropical fish breeding became popular especially after the Second World War. This is because rare live fish were imported from overseas, many varieties were artificially bred, and feed, breeding facilities, and management were significantly improved, making them widely available to ordinary households. As a result, many rare and endangered species are being kept as ornamental fish, which has become a problem.

Coral fish are representative of saltwater fish, and there are many small species with a wide variety of colors, including butterflyfish, damselfish, wrasses, and triggerfish, which are popular among ornamental fish enthusiasts. Saltwater fish were generally more difficult to raise and care for than freshwater fish, but breeding equipment has improved significantly, making them easy to raise even for amateurs.

[Akira Ochiai and Kunio Amanooka, March 19, 2015]

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

水槽や池などでペットとして飼育し、観賞して楽しみ、憩いを与えてくれる魚類の総称。姿や形、色合いの美しさや変わった習性などが観賞される。淡水魚と海水魚に大別される。淡水魚で代表的なものは、キンギョ、ニシキゴイ、熱帯魚などである。キンギョは、中国で8、9世紀に品種改良がされだし、17世紀の初めにヨーロッパに伝わってから世界的な観賞魚となった。現在では多数の品種が育成され、日本でも20種を超える。ニシキゴイ（錦鯉）は、イロゴイ（色鯉）ともよばれ、19世紀の前半に、現在の新潟県長岡市（おもに南東部の旧、古志(こし)郡）などで、マゴイの色変わりを飼育しだしたのが始まりである。以後、交配により品種が増えて数十種もあり、現在ではキンギョとともに外国へも輸出されている。観賞用の熱帯魚は、アジア、アフリカ、中央・南アメリカの熱帯が原産地である。メダカ類、カワスズメ類、ナマズ類、ドジョウ類、カラシン類などに観賞の対象となるものが多い。熱帯魚の飼育は、ことに第二次世界大戦後に盛んになった。これは、外国から珍しい活魚を輸入し、多くの品種が人工的に育成され、飼料や飼育設備および管理が著しく改善されて、一般家庭にも広く普及したためである。それに伴い、多くの希少種や絶滅危惧(きぐ)種などが飼育・観賞の魚類の対象とされ問題となっている。

　海水魚で代表的なものはコーラルフィッシュ（サンゴ礁魚類）で、小形で色彩も変化に富む種類が多く、チョウチョウウオ類、スズメダイ類、ベラ類、モンガラカワハギ類などは観賞魚として愛好者に親しまれている。海水魚は飼育管理が淡水魚に比べて全般的にむずかしかったが、飼育装置が著しく改良され素人(しろうと)でも簡単に飼育できるようになった。

［落合　明・尼岡邦夫　2015年3月19日］

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